This specification generally relates to information presentation.
Sponsored content (e.g. advertisements) can be provided over the Internet to various user devices. For example, a resource (e.g., web page) can include content item display environments (e.g., advertisement slots such as iFrames) in which sponsored content can be presented. These environments can be defined in the resource or defined for presentation with the resource, for example, along with search results or other content. Sponsored content can also be delivered through dedicated web portals or applications executing on user devices.